Loki (mcu)
Hydra was founded on a very simple belief. Humanity can not be trusted with its own freedom. You did what we they tried to do in the beginning and take it by force. That only leads to resistance.
The organization was founded in early days of World War II by Johann Schmidt. The Nazi party proved to be fertile soil for the fledgling group but soon became too restrictive. Too small minded. That belief system was flawed. Schmidt separated from the party. Hydra fought both the allies and the axis. There was a good chance it would've been victorious if not for Captain America and the disappearance of Schmidt.
While defeated at the end of the war, the SSR recruited Arnim Zola and allowed him to work for them. He spent that time growing a new Hydra within the SSR and then SHIELD. Until recently, the new Hydra was subtle. They lived in shadows and silently started wars or acts of civil unrest. When needed, I eliminated those who could be threats or pulled off high level assassinations. The belief was that if we created enough chaos humanity would give up their freedom willingly.
It worked. Project Insight was the culmination of Hydra's efforts since the war. With it we they could monitor the world and take out those who would cause trouble in the future with just the push of a button. Hydra would finally bring order to the world.
Captain America stopped us... and Fury killed Pierce.